[PATCH v3 09/11] platform/x86: asus-wmi: Control RGB keyboard backlight

From: Yurii Pavlovskyi
Date: Fri Apr 19 2019 - 14:23:40 EST


The WMI exposes two methods for controlling RGB keyboard backlight, which
allows controlling:
* RGB components in range 00 - ff,
* Switch between 4 effects,
* Switch between 3 effect speed modes,
* Separately enable the backlight on boot, in the awake state (after driver
load), in sleep mode, and probably in something called shutdown mode (no
observable effects of enabling it are known so far).

The configuration should be written to several sysfs parameter buffers
which are then written via WMI by writing either 1 or 2 to the "kbbl_set"
parameter. When reading the buffers the last written value is returned.

If the 2 is written to "kbbl_set", the parameters will be reset on reboot
(temporary mode), 1 is permanent mode, parameters are retained.

The calls use new 3-dword input buffer method call.

The functionality is only enabled if corresponding DSTS methods return
exact valid values.

The following script demonstrates usage:

echo Red [00 - ff]
echo 33 > /sys/devices/platform/asus-nb-wmi/kbbl/kbbl_red
echo Green [00 - ff]
echo ff > /sys/devices/platform/asus-nb-wmi/kbbl/kbbl_green
echo Blue [00 - ff]
echo 0 > /sys/devices/platform/asus-nb-wmi/kbbl/kbbl_blue
echo Mode: 0 - static color, 1 - breathing, 2 - color cycle, 3 - strobing
echo 0 > /sys/devices/platform/asus-nb-wmi/kbbl/kbbl_mode
echo Speed for modes 1 and 2: 0 - slow, 1 - medium, 2 - fast
echo 0 > /sys/devices/platform/asus-nb-wmi/kbbl/kbbl_speed
echo Enable: 02 - on boot, before module load, 08 - awake, 20 - sleep,
echo 2a or ff to set all
echo 2a > /sys/devices/platform/asus-nb-wmi/kbbl/kbbl_flags
echo Save: 1 - permanently, 2 - temporarily, reset after reboot
echo 1 > /sys/devices/platform/asus-nb-wmi/kbbl/kbbl_set

Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@xxxxxxxxx>
---
.../ABI/testing/sysfs-platform-asus-wmi | 61 ++++
drivers/platform/x86/asus-wmi.c | 331 ++++++++++++++++++
include/linux/platform_data/x86/asus-wmi.h | 2 +
3 files changed, 394 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-platform-asus-wmi b/Documentation/ABI/testing/sysfs-platform-asus-wmi
index 019e1e29370e..1cc54d5e3e10 100644
--- a/Documentation/ABI/testing/sysfs-platform-asus-wmi
+++ b/Documentation/ABI/testing/sysfs-platform-asus-wmi
@@ -36,3 +36,64 @@ KernelVersion: 3.5
Contact: "AceLan Kao" <acelan.kao@xxxxxxxxxxxxx>
Description:
Resume on lid open. 1 means on, 0 means off.
+
+What: /sys/devices/platform/<platform>/kbbl/kbbl_red
+Date: Apr 2019
+KernelVersion: 5.1
+Contact: "Yurii Pavlovskyi" <yurii.pavlovskyi@xxxxxxxxx>
+Description:
+ RGB keyboard backlight red component: 00 .. ff.
+
+What: /sys/devices/platform/<platform>/kbbl/kbbl_green
+Date: Apr 2019
+KernelVersion: 5.1
+Contact: "Yurii Pavlovskyi" <yurii.pavlovskyi@xxxxxxxxx>
+Description:
+ RGB keyboard backlight green component: 00 .. ff.
+
+What: /sys/devices/platform/<platform>/kbbl/kbbl_blue
+Date: Apr 2019
+KernelVersion: 5.1
+Contact: "Yurii Pavlovskyi" <yurii.pavlovskyi@xxxxxxxxx>
+Description:
+ RGB keyboard backlight blue component: 00 .. ff.
+
+What: /sys/devices/platform/<platform>/kbbl/kbbl_mode
+Date: Apr 2019
+KernelVersion: 5.1
+Contact: "Yurii Pavlovskyi" <yurii.pavlovskyi@xxxxxxxxx>
+Description:
+ RGB keyboard backlight mode:
+ * 0 - static color,
+ * 1 - breathing,
+ * 2 - color cycle,
+ * 3 - strobing.
+
+What: /sys/devices/platform/<platform>/kbbl/kbbl_speed
+Date: Apr 2019
+KernelVersion: 5.1
+Contact: "Yurii Pavlovskyi" <yurii.pavlovskyi@xxxxxxxxx>
+Description:
+ RGB keyboard backlight speed for modes 1 and 2:
+ * 0 - slow,
+ * 1 - medium,
+ * 2 - fast.
+
+What: /sys/devices/platform/<platform>/kbbl/kbbl_flags
+Date: Apr 2019
+KernelVersion: 5.1
+Contact: "Yurii Pavlovskyi" <yurii.pavlovskyi@xxxxxxxxx>
+Description:
+ RGB keyboard backlight enable flags (2a to enable everything), OR of:
+ * 02 - on boot (until module load),
+ * 08 - awake,
+ * 20 - sleep.
+
+What: /sys/devices/platform/<platform>/kbbl/kbbl_set
+Date: Apr 2019
+KernelVersion: 5.1
+Contact: "Yurii Pavlovskyi" <yurii.pavlovskyi@xxxxxxxxx>
+Description:
+ Write changed RGB keyboard backlight parameters:
+ * 1 - permanently,
+ * 2 - temporarily.
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 1b8272374660..0a32079336d8 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -148,6 +148,21 @@ struct asus_rfkill {
u32 dev_id;
};

+struct asus_kbbl_rgb {
+ u8 kbbl_red;
+ u8 kbbl_green;
+ u8 kbbl_blue;
+ u8 kbbl_mode;
+ u8 kbbl_speed;
+
+ u8 kbbl_set_red;
+ u8 kbbl_set_green;
+ u8 kbbl_set_blue;
+ u8 kbbl_set_mode;
+ u8 kbbl_set_speed;
+ u8 kbbl_set_flags;
+};
+
struct asus_wmi {
int dsts_id;
int spec;
@@ -183,6 +198,9 @@ struct asus_wmi {
int asus_hwmon_num_fans;
int asus_hwmon_pwm;

+ bool kbbl_rgb_available;
+ struct asus_kbbl_rgb kbbl_rgb;
+
struct hotplug_slot hotplug_slot;
struct mutex hotplug_lock;
struct mutex wmi_lock;
@@ -658,6 +676,312 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
return rv;
}

+/* RGB keyboard backlight *****************************************************/
+
+static ssize_t show_u8(u8 value, char *buf)
+{
+ return scnprintf(buf, PAGE_SIZE, "%02x\n", value);
+}
+
+static ssize_t store_u8(u8 *value, const char *buf, int count)
+{
+ int err;
+ u8 result;
+
+ err = kstrtou8(buf, 16, &result);
+ if (err < 0) {
+ pr_warn("Trying to store invalid value\n");
+ return err;
+ }
+
+ *value = result;
+
+ return count;
+}
+
+static ssize_t kbbl_red_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return show_u8(asus->kbbl_rgb.kbbl_red, buf);
+}
+
+static ssize_t kbbl_red_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return store_u8(&asus->kbbl_rgb.kbbl_set_red, buf, count);
+}
+
+static ssize_t kbbl_green_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return show_u8(asus->kbbl_rgb.kbbl_green, buf);
+}
+
+static ssize_t kbbl_green_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return store_u8(&asus->kbbl_rgb.kbbl_set_green, buf, count);
+}
+
+static ssize_t kbbl_blue_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return show_u8(asus->kbbl_rgb.kbbl_blue, buf);
+}
+
+static ssize_t kbbl_blue_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return store_u8(&asus->kbbl_rgb.kbbl_set_blue, buf, count);
+}
+
+static ssize_t kbbl_mode_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return show_u8(asus->kbbl_rgb.kbbl_mode, buf);
+}
+
+static ssize_t kbbl_mode_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return store_u8(&asus->kbbl_rgb.kbbl_set_mode, buf, count);
+}
+
+static ssize_t kbbl_speed_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return show_u8(asus->kbbl_rgb.kbbl_speed, buf);
+}
+
+static ssize_t kbbl_speed_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return store_u8(&asus->kbbl_rgb.kbbl_set_speed, buf, count);
+}
+
+static ssize_t kbbl_flags_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return show_u8(asus->kbbl_rgb.kbbl_set_flags, buf);
+}
+
+static ssize_t kbbl_flags_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct asus_wmi *asus = dev_get_drvdata(dev);
+
+ return store_u8(&asus->kbbl_rgb.kbbl_set_flags, buf, count);
+}
+
+static ssize_t kbbl_set_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return scnprintf(buf, PAGE_SIZE,
+ "Write to configure RGB keyboard backlight\n");
+}
+
+static int kbbl_rgb_write(struct asus_wmi *asus, int persistent)
+{
+ int err;
+ u32 retval;
+ u8 speed_byte;
+ u8 mode_byte;
+ u8 speed;
+ u8 mode;
+
+ speed = asus->kbbl_rgb.kbbl_set_speed;
+ switch (speed) {
+ case 0:
+ default:
+ speed_byte = 0xe1; // slow
+ speed = 0;
+ break;
+ case 1:
+ speed_byte = 0xeb; // medium
+ break;
+ case 2:
+ speed_byte = 0xf5; // fast
+ break;
+ }
+
+ mode = asus->kbbl_rgb.kbbl_set_mode;
+ switch (mode) {
+ case 0:
+ default:
+ mode_byte = 0x00; // static color
+ mode = 0;
+ break;
+ case 1:
+ mode_byte = 0x01; // breathing
+ break;
+ case 2:
+ mode_byte = 0x02; // color cycle
+ break;
+ case 3:
+ mode_byte = 0x0a; // strobing
+ break;
+ }
+
+ err = asus_wmi_evaluate_method_3dw(ASUS_WMI_METHODID_DEVS,
+ ASUS_WMI_DEVID_KBD_RGB,
+ (persistent ? 0xb4 : 0xb3) |
+ (mode_byte << 8) |
+ (asus->kbbl_rgb.kbbl_set_red << 16) |
+ (asus->kbbl_rgb.kbbl_set_green << 24),
+ (asus->kbbl_rgb.kbbl_set_blue) |
+ (speed_byte << 8), &retval);
+ if (err) {
+ pr_warn("RGB keyboard device 1, write error: %d\n", err);
+ return err;
+ }
+
+ if (retval != 1) {
+ pr_warn("RGB keyboard device 1, write error (retval): %x\n",
+ retval);
+ return -EIO;
+ }
+
+ err = asus_wmi_evaluate_method_3dw(ASUS_WMI_METHODID_DEVS,
+ ASUS_WMI_DEVID_KBD_RGB2,
+ (0xbd) |
+ (asus->kbbl_rgb.kbbl_set_flags << 16) |
+ (persistent ? 0x0100 : 0x0000), 0, &retval);
+ if (err) {
+ pr_warn("RGB keyboard device 2, write error: %d\n", err);
+ return err;
+ }
+
+ if (retval != 1) {
+ pr_warn("RGB keyboard device 2, write error (retval): %x\n",
+ retval);
+ return -EIO;
+ }
+
+ asus->kbbl_rgb.kbbl_red = asus->kbbl_rgb.kbbl_set_red;
+ asus->kbbl_rgb.kbbl_green = asus->kbbl_rgb.kbbl_set_green;
+ asus->kbbl_rgb.kbbl_blue = asus->kbbl_rgb.kbbl_set_blue;
+ asus->kbbl_rgb.kbbl_mode = mode;
+ asus->kbbl_rgb.kbbl_speed = speed;
+
+ return 0;
+}
+
+static ssize_t kbbl_set_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ u8 value;
+ struct asus_wmi *asus;
+ int result;
+
+ asus = dev_get_drvdata(dev);
+ result = store_u8(&value, buf, count);
+ if (result < 0)
+ return result;
+
+ if (value == 1)
+ kbbl_rgb_write(asus, 1);
+ else if (value == 2)
+ kbbl_rgb_write(asus, 0);
+
+ return count;
+}
+
+/* RGB values: 00 .. ff */
+static DEVICE_ATTR_RW(kbbl_red);
+static DEVICE_ATTR_RW(kbbl_green);
+static DEVICE_ATTR_RW(kbbl_blue);
+
+/*
+ * Color modes: 0 - static color, 1 - breathing, 2 - color cycle, 3 - strobing
+ */
+static DEVICE_ATTR_RW(kbbl_mode);
+
+/* Speed for modes 1 and 2: 0 - slow, 1 - medium, 2 - fast */
+static DEVICE_ATTR_RW(kbbl_speed);
+
+/*
+ * Enable: 02 - on boot (until module load) | 08 - awake | 20 - sleep
+ * (2a or ff to enable everything)
+ *
+ * Logically 80 would be shutdown, but no visible effects of this option
+ * were observed so far
+ */
+static DEVICE_ATTR_RW(kbbl_flags);
+
+/* Write data: 1 - permanently, 2 - temporarily (reset after reboot) */
+static DEVICE_ATTR_RW(kbbl_set);
+
+static struct attribute *rgbkb_sysfs_attributes[] = {
+ &dev_attr_kbbl_red.attr,
+ &dev_attr_kbbl_green.attr,
+ &dev_attr_kbbl_blue.attr,
+ &dev_attr_kbbl_mode.attr,
+ &dev_attr_kbbl_speed.attr,
+ &dev_attr_kbbl_flags.attr,
+ &dev_attr_kbbl_set.attr,
+ NULL,
+};
+
+static const struct attribute_group kbbl_attribute_group = {
+ .name = "kbbl",
+ .attrs = rgbkb_sysfs_attributes
+};
+
+static int kbbl_rgb_init(struct asus_wmi *asus)
+{
+ int err;
+
+ err = asus_wmi_get_devstate_simple(asus, ASUS_WMI_DEVID_KBD_RGB);
+ if (err) {
+ if (err == -ENODEV)
+ return 0;
+ else
+ return err;
+ }
+
+ err = asus_wmi_get_devstate_simple(asus, ASUS_WMI_DEVID_KBD_RGB2);
+ if (err) {
+ if (err == -ENODEV)
+ return 0;
+ else
+ return err;
+ }
+
+ asus->kbbl_rgb_available = true;
+ return sysfs_create_group(&asus->platform_device->dev.kobj,
+ &kbbl_attribute_group);
+}
+
+static void kbbl_rgb_exit(struct asus_wmi *asus)
+{
+ if (asus->kbbl_rgb_available) {
+ sysfs_remove_group(&asus->platform_device->dev.kobj,
+ &kbbl_attribute_group);
+ }
+}
+
/* RF *************************************************************************/

/*
@@ -2230,6 +2554,10 @@ static int asus_wmi_add(struct platform_device *pdev)
if (err)
goto fail_leds;

+ err = kbbl_rgb_init(asus);
+ if (err)
+ goto fail_rgbkb;
+
asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_WLAN, &result);
if (result & (ASUS_WMI_DSTS_PRESENCE_BIT | ASUS_WMI_DSTS_USER_BIT))
asus->driver->wlan_ctrl_by_user = 1;
@@ -2287,6 +2615,8 @@ static int asus_wmi_add(struct platform_device *pdev)
fail_backlight:
asus_wmi_rfkill_exit(asus);
fail_rfkill:
+ kbbl_rgb_exit(asus);
+fail_rgbkb:
asus_wmi_led_exit(asus);
fail_leds:
fail_hwmon:
@@ -2307,6 +2637,7 @@ static int asus_wmi_remove(struct platform_device *device)
asus_wmi_backlight_exit(asus);
asus_wmi_input_exit(asus);
asus_wmi_led_exit(asus);
+ kbbl_rgb_exit(asus);
asus_wmi_rfkill_exit(asus);
asus_wmi_debugfs_exit(asus);
asus_wmi_platform_exit(asus);
diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
index a5fe7e68944b..c8c6e939e196 100644
--- a/include/linux/platform_data/x86/asus-wmi.h
+++ b/include/linux/platform_data/x86/asus-wmi.h
@@ -57,6 +57,8 @@
#define ASUS_WMI_DEVID_KBD_BACKLIGHT 0x00050021
#define ASUS_WMI_DEVID_LIGHT_SENSOR 0x00050022 /* ?? */
#define ASUS_WMI_DEVID_LIGHTBAR 0x00050025
+#define ASUS_WMI_DEVID_KBD_RGB 0x00100056
+#define ASUS_WMI_DEVID_KBD_RGB2 0x00100057

/* Misc */
#define ASUS_WMI_DEVID_CAMERA 0x00060013
--
2.17.1